How long does Topamax stay in your system?

Topamax stays in your system for approximately 4 to 5 days after the last dose, but this may vary depending on personal factors, such as your age, weight, dosage, and what other medications you currently take. This estimate is based on the half-life of Topamax which is about 21 hours and experts agree that it takes up to 5 half-lives for a drug without active metabolites to be completely removed from the body (a drug’s half-life is the time it takes for 50% of that drug to be removed from the body). Topamax does have some metabolites, but these are not considered active and only make up about 5% of an administered dose. This means it takes 84 to 105 hours for Topamax to leave your body.

Topamax should never be stopped suddenly or “cold turkey”, because this may cause you to have an increased risk of seizures, more frequent seizures, or other serious withdrawal symptoms. This can happen even if you do not take Topamax for epilepsy. Topamax is also approved by the FDA to be used in patients to help prevent migraine headaches.

To decrease the risk for seizures or other withdrawal symptoms, your doctor will let you know how to slowly stop taking Topamax. Depending upon the dose you take, it may take several weeks to a few months to slowly discontinue Topamax.